DESCRIPTION: (Investigator's Abstract) Intraocular hyperthermia, IHT, is being investigated as an adjunct to ionizing radiation therapy as a means of improving therapeutic response while minimizing undesired side effects. For microwave, radio frequency or ultrasound inducing IHT it has been difficult to localize such heating to the tumor tissue. It is proposed to develop a system for intraocular laser induced hyperthermia, ILHT. Emphasis in Phase-I is to develop the necessary delivery systems and testing of them in an appropriate animal model. The system is to include both a transcorneal approach and a transcleral approach. The laser to be used is the 1064nm NdYAG due to its deep penetration in tissue. The delivery systems will emphasis the ability to irradiate a large area >1.0 cm in diameter, with uniform irradiance. Testing is to be done in rabbits with and without transplanted choroidal tumors. Testing in phase-I will include on line thermal monitoring in the animal systems along with thermal modeling of the response. Limited results to date by Gomer and Svaasand, with crude delivery devices, have been promising. If the proper delivery devices and overall system can be developed ILHT could find a significant use in the management of intraocular tumors in combination with other therapies. Its commercial potential could be significant if it can be made cost effective and easy to use, which is the specific aim of this proposal.